Scientists develop new molecular test for influenza infection
Scientists designed the molecular test by evaluating real-time polymerase chain reaction assays to look at growth and subtyping of both common influenza strands, H3N2 and H1N1, or types A and B respectively, along with detecting drug-resistant mutations from four assays.
87 patients across Asia, Europe and the United States were taken as participants in the study and 245 respiratory specimens were observed to diagnose influenza illness and possible neuraminidase resistance. Ninety-six pre-pandemic influenza A viruses between 2007-2008 were analyzed by the H275Y assay to check the robustness of the assay.
RT-PCR assays were used to detected resistance mutations in the Influenza A virus. One hundred twenty-nine of the specimens observed tested positive for strands A and B; one specimen tested positive for both.
"The assays described here cover all currently circulating human influenza viruses and can detect major resistance mutations to oseltamivir," Head of the Clinical Virology Unit at the Erasmus University Martin Schutten said. "By introducing external quantification and internal standards, longitudinal assay performance can be monitored carefully and a virus particle count can be assigned to an analyzed sample.
Schutten also said this algorithm can be used to obtain information about the influenza virus, viral load and antiviral susceptibility of an infected patient within one day, the fastest testing yet. He said this can also be used as a tool for clinical management of the influenza virus, since its antiviral mutation can be detected.
Although the most common strands of the influenza virus are types A and B, other strands do exist and pose a threat to people worldwide. Similar methods for detection of infection from H7N9 or H5N1, new emerging strands, may potentially be developed.